This invention relates to the field of filling aerosol spray paint cans or similar items. When an aerosol spray paint can is charged, it is necessary to place a ball inside the can. This ball permits the user to stir the contents of the can by shaking the can with the ball inside.
Aerosol spray paint cans and the like are normally filled and sealed by automatic mass production. A conveyor belt type arrangement is used whereby the cans are placed on a conveyor belt which has placer tabs for each can and receive charges of contents. The cans are eventually crimped and sealed for transportation and sale. During this charging process it is necessary for the manufacturer to insert a ball inside of each can. Should a ball fail to be inserted in the can the finished product would not be marketable. It is therefore important in the industry to insure that each can receives a ball before the can is sealed.
Other manufacturing processes also require that balls be inserted into a can before it is permanently sealed. Any industry which utilizes a ball inside of a sealed container would benefit from this device and the method for using same.
One major problem which exists in automatically checking the insertion of a ball into a can is that the spray paint industry (and other related industries) use highly volatile chemicals in filling the contents of the can prior to the insertion of the ball. For example, in the spray paint industry, acetone and methyl chloride must be placed into the can before it is sealed. Both of these chemicals are highly volatile and the use of electrically powered checking devices is severely restricted and quite hazardous.
It is an object of this invention to provide an automatic ball drop checking device which utilizes only pneumatic sensing devices and pneumatic power for its operation. The use of air pressure rather than electricity greatly enhances the safety of the instant automatic checking device.
It is another object of this invention to provide a method which may be universally adapted for use in counting materials when electronic counters or other electronic devices would be impractical or hazardous.